it has to have sufficient mass to overcome its compressive strength and achieve hydrostatic equilibrium
Needs to have enough gravity to pull itself into a spherical shape
Rounded by it's own gravitational pull
Needs to have “cleared the neighborhood” around it
Has not “cleared the neighborhood” around it
hydrostatic equilibrium occurs when compression, caused by gravity, is balanced by a pressure gradient, which creates force in the opposite direction. The inward pressure is counteracted by the external pressure of the atmosphere.
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http://www.typewith.me/pgQpg1HzGl
Dabble Board: http://www.dabbleboard.com/draw?b=Guest489549&i=0&c=541c5fd1830a37453eded8b89fa258364541a84b
Picture citations:
"our solar system." OUR SOLAR SYSTEM. bing.com, Web. 15 Nov. 2010. http://library.thinkquest.org/25097/graphics/main.jpg.
"The Pluto System on Feb. 15, 2006 (Non-annotated)." BBLE. bing.com, Web. 15 Nov. 2010. <http://www.spacetelescope.org/static/archives/images/screen/opo0609b.jpg>.
"The Planet Pluto." Poor William's Almanack. bing.com, 18 Feb. 2009. Web. 15 Nov. 2010. http://www.poorwilliam.net/pix/pluto-planet2.jpg
Citations:
Conan-Davies, Richard. "The Plantes." Clearly Explained.Com. N.p., 31 July 2005. Web. 16 Nov. 2010. http://clearlyexplained.com/nature/space/planets/index.html.
Cain, Fraser. "Why Pluto is No Longer A Planet." Universe Today, 1999. Web. 16 Nov. 2010.
http://www.universetoday.com/13573/why-pluto-is-no-longer-a-planet/.
"Pluto." History .com. A&E Television Networks, 1996-2010. Web. 16 Nov. 2010.
http://www.history.com/topics/pluto.
"What is hydrostatic equilibreum?." Wiki Answers. N.p., n.d. Web. 16 Nov. 2010. http://wiki.answers.com/Q/What_is_hydrostatic_equilibrium&alreadyAsked=1&rtitle=Why_does_sun_maintain_size_and_shape.